Binary to decimal converter tube



1953 F; B. MAYNARD 2,362,127

BINARY TO DECIMAL CONVERTER TUBE Filed May 17, 1954 s Sheets-Sheet 1 fl/A/AEY 007/ 07 2&2220

IN VEN TOR. FEED 5. MA YIVAED /6 ATTOEA EK Nov. 25, 1958 F. B. MAYNARD BINARY TO DECIMAL CONVERTER TUBE 3 Sheets-Sheet 2 Filed May 17, 1954 7'0 Ge/D 62 I N V EN TORv FEED 5. MA wv/aeo A TTOENEK Nov. 25, 1958 F. B. MAYNARD 2,362,127

BINARY TO DECIMAL CONVERTER TUBE Filed May 17. 1954 s Sheets-Sheet 3 7'0 GRIDS 63/, 632, 633 7' 0 GRIPS 634, 636, 637

+ 2 f 70 62/0 6/ C TO ale/0 e2 INVENTOR.

F250 5. MA Y/VAED V A it BINARY TO DECIMAL CONVERTER TUBE Application May 17, 1954, Serial No. 430,300

3 Claims. (Cl. 313-73) This invention relates to electron tubes and more especially to converter tubes for use in electronic computer systems and the like.

A principal object of the invention is to provide a simplified and easily manufactured electron tube for converting input voltages representing one class of digits, for example decimal digits, into output voltages representing another class of digits, for example those used in the well-known binary system.

A feature of the invention relates to anovel and symmetrical electrode arrangement for an electron tube whereby a decimal-digit input voltage can be directly translated into binary number output voltages, and vice versa.

Another feature relates to a novel and symmetrical electrode arrangement for an electron tube whereby signal voltages representing a number in the binary system are converted into a single voltage representing a number in the decimal system.

Another feature relates to an electron tube of the multi-chan'nel gating type wherein a single central electron emitter is surrounded concentrically with a series of gating control grids each of which cooperates with one or a plurality of collectors or anodes. These anodes are interconnected in preselected combinations so that the application of any single voltage representing for example a decimal digit, results in the application simultaneously of on-oi'f voltage conditions in permuted corn-.

binations in so-called binary computer wires.

A further feature relates to the novel. organization,

arrangement, and relative location and interconnection of parts which cooperate to provide an improved signal converter tube for converting numbers in one computing system to numbers in a diiterent computing system.

Other features and advantages not particularly enumerated will be apparent after a consideration of the following detailed descriptions and the appended claims.

In the drawing which shows, by way of example,- one preferred embodiment,

Fig. 1 is a schematic plan view of a tube and converting system according to the invention;

Fig. 2 is a perspective view of part, of the tube of Fig. 1;

Fig. 3 is a schematic plan view of a modification of the tube and converting system according to the invention; a

Fig. 4 is a schematic plan view of a further modification of the invention.

Referring to Figs. 1 and 2 there is shown a tube for the conversion of an input voltage representing for example a digit in the decimal system, to a permuted combination of voltages or lack-of voltages on a plurality.

of so-called binary wires. Thus, for purposes of illustration, assuming a system employing sixteen decimal digits to #15, these digits can be represented on five so-called binary wires according to the well-known arrangement illustrated as follows:

States Patent 0 ice Decimal Digit In the foregoing chart the letter x indicates that the corresponding binary wire has a voltage impressed thereon or is in the on condition, whereas the absence of the letter x indicates the corresponding binary wire is deenergized or in the off condition, thus enabling each wire to control any well-known binary or flip-flop type of control circuit. Referring to Figs. 1 and 2 of the drawing, the tube comprises an enclosing evacuated glass bulb B containing a central electron-emitting cathode 16 which may be of any well-known type such as is used conventionaly in so-called indirectly heated cathodes. It may comprise, for example, a tubular metal sleeve, the periphery of which is coated with any well-known thermionic electron-emissive material. The sleeve is arranged to be heated by any well-known internal heater element. Surrounding the cathode 16 concentrically are two accelerating grids 17, 18, which may be connected torsuitable positive biasing potentials so' as to accelerate the electrons from the cathode 16 to the required degree. concentrically surrounding the cathode 16 and grids 17, 18, is a circumferential array of sixteen discrete gating control grids numbered 0 to 15. These grids may be of any Well-known open work or foraminous structure and are designed so that normally they are connected to a suitable negative potential so as to bias them to plate current cutoff. Each grid may comprise a pair of metal side rods across which extend the spaced final wire grid laterals as shown in Fig. 2.

Suitably mounted in radial alignment with each of the gating grids is one of a series of 33 electron collector electrodes designated C C If desired, a foraminous shield grid 19Vcan surround all the preceding electrodes and this shield grid can be connected to a suitable positive potential. Each of the gating grids is provided with a separate lead-in member designated respectively G to G so that each grid may be separately energized by a suitable positive input signal representing the respective decimal digit. For example, if the input signal represents the decimal digit zero, only the gating grid #0 will have a positive potential applied thereto so that the electrons from the cathode 16 will. pass only through the grid #0 to the corresponding electron electrode C which thereupon assumes a steady negative potential.

to gating grid #3 and the electrons from the cathode 16 will be gated only by that grid so as to reach only the collector electrodes C C In order that each collector electrode may receive the same amount of electron flow when its associated grid is gated on, these collectors should all have the same area and should all subtend the same angle with respect to the cathode.

Since the tube is designed to convert any one of 15 input decimal input digit signals into corresponding binary output signals, the gating grids will have either 1,

2, 3 or 4 collector electrodes in radial registry therewith. For example, gating grids 0, 1, 2, 4, 8, have in radial registry therewith a corresponding single collector electrode C C C C grids 3, 5, 6, 9, 10 and 12, has in radial registry therewith a corresponding pair of collector electrodes, namely (C5! C6), (C7: C8)! (C9, C10)? (C11, C12): (C13, C14): (C C Each of the gating control grids 7, 11, 13 and 14, has in radial registry therewith a set of three collector electrodes. Thus the set of collectors C C C are in radial registry with grid #7. Collector electrodes C C C are in radial registry with, grid #11. Collector electrodes C C C are in registry with grid #13. Collector electrodes C C 7, C are in registry with grid #14. The grid 15 has a series of four collector electrodes C29, C C C in radial registry therewith.

The #0 grid and its collector electrode C are. con? nected to the #0 wire of a set of five binary output wires. The collector electrodes C C C7, C C C C C are all connected together by a conductor 20 and thence to the #1 Wire. of the binary output wires. Collector electrodes C2, C6,. C C13, C18, C21, C C C are connected together by a conductor 21 and thence to the #2 wire of the five binary outputs. COllCCtOT i$CiIOdS C3, C3, C10, C15, C19, C24, C27, C31,

7' are connected together by a conductor 22 and thence to the #3 wireof the five binary outputs. Finally, collector electrodes C C C C C22, C25, C and C are connected together by a wire 23 and thence to the #4 wire of the five binary outputs.

From the foregoing it will be seen that by applying the appropriate signal representing a decimal-digit to the corresponding control grid it is possible to set up on the five binary output wires the corresponding off and on potential combinations as indicated hereinabove. It will be understood, of course, that each of the controlgrids #0 to #15 is provided with a separate lead-in member (not shown) which can be sealed through the base or header or any other convenient portion of the wall of tube B.

While in the embodiment of Figs. 1 and 2, the device is arranged to translate an input voltage representing a decimal digit into a combination of off and on conditions on binary code wires representing the corresponding binary member, it may be desirable to reverse the process. Fig. 3 shows a device for accomplishing this reverse conversion. In other words, the input signals may be those received for example from the five binary leads 20, 21, 22, 23, 24 (Fig. 1) which are to be converted into a single corresponding output voltage representing the corresponding decimal digit. A device for accomplishing this purpose is shown in schematic plan view in Fig. 3. Merely for simplicity in the drawing, the device is shown employing only three sets of binary input wires, namely 2, 2 2 although obviously any greater or less number may be employed withcorresponding increase in the number of electrodes.

Referring to Fig. 3, the device comprises the evacuated enclosing bulb or envelope B having the usual header through which are sealed in a vacuum-tight manner the various lead-in wires to the various electrodes. Suitably supported within the bulb B centrally thereof is the elongated tubular electron-emitting cathode 31 which may be similar to the cathode 16 of Fig. l.

Suitably supported concentrically around the cathode 31 are a series of eight parallel metal rods 32 which extend parallel to the length of the cathode 31 and are equally spaced from each other therearound. These rods may be connected to a single lead-in (not shown) for connection to a suitable positive potential whereby the electrons from the cathode are accelerated to the required degree. cathode are a series of eight collector plates or anodes designated respectively #0 to #7. Each of these electron Each of the gating control Concentrically surrounding the.

collector electrodes has the same circumferentialarcuate width so that each subtends the same angle with respect to the cathode. Also concentrically surrounding the cathode are a series of eight gating control grids designated respectively G30 to G37. Each of these grids is mounted in front of a corresponding one of the collector electrodes as shown in the drawing. Each grid may comprisea pairof parallel supporting side rods 33, 34, across which extend the parallel fine wire grid laterals which constitute the grid. It will be understood, of course, that any well-known form of foraminous structure may be used for these grids. Preferably, the side rods 33 and 34 are-arranged so that the effective arcuate width of each gating grid G30-G37 is equal to the arcuate width of the corresponding collector electrode. The gating grids G32G37 are interconnected in alternate pairs by means of wires 35, 36, 37, 38, 39. Thus, wire 35 connects grid G32 directly to grid G31; wire 36 connects grid G36 directly to grid G35; wire 37 connects grid G31 to grid 33; wire 38 connectsgrid G35 to grid G37; and wire 39 connects grid G30 to grid G32.

Also concentrically surrounding the cathode is another set of four gating control grids G20-G23. The grids of this. second set are also provided with respective parallel side rod supports 21, 22, across which extend the fine wire,

same angle as both grids G31, G35. Grid G23 subtends.

the same angle as both grids G33 and G37.

Similarly, concentrically surrounding the cathode G31 is a third set of two gating control grids G1, G2, each supported on respective side rods 23, 24. The grids G1 and G2 are of equal circumferential arcuate width, and each subtends at the cathode an angle substantially the same as that subtended by a pair of gating grids. For example, grid G1 subtends the same angle as both the grids G20 and G21 together. Grid G2 subtends the same angle as both grids G22 and G23 together. were not for the fact that the gating grids are to be mechanically spaced, the grids G1 and G2 might be considered as being approximately degrees in arcuate width. In. any event the various gating grids are supported. with their corresponding respective side rods in radial alignment so as to cause a minimum amount of electron shadow between successive grids. Likewise, preferably the accelerating grid side rods 32a, 32b, 32c, 32d are mounted diagonally opposite to each other and in alignment with the spaces between the ends of the corresponding gating grid pairs so as to cast the minimum electron shadow on the said gating control grids.

Each collector electrode is provided with a separate sealed-in conductor by means of which each collector can be connected to a separate utilization circuit, such for example as a computator circuit element which responds to successive voltages representing successive decimal digits. 2

The gating grids G30, G31, G32, G33, are connected to a single lead-in member 40; gating grids G34, G35, G36, G37, are likewise connected to a single lead-in member 41. Similarly, the gating grids G20, G22 are connected to a single lead-in 42; and gating grids G21, G23, areconnected to a single lead-in 43. In like manner, gating grid G1 is connected to lead-in member 44; and gating grid G2 is. connected to lead-in 45. Therefore, by applying suitable on and off potential pulses to these various lead-ins in accordance with the above chart, a particular one of the collector electrodes alone is gated into circuit. In other words, for any given combination of pulse and no-pulse potentials applied to the pairsof If it.

lead-ins, there is only one conductive path between the cathode 31 and the particular collector. electrode repre senting the desired decimal digit.

When a gating on voltage pulse, for example a positive pulse, is applied to one-half the number of grids in one set of gating grids, an oil voltage is also simultaneously applied to the remaining half of the number of grids in the same set. For example, if the incoming binary signal Voltage 'is'to represent the output decimaldigit #1,a' positive or on voltage pulse is applied to lead-in 40 and a negative or ofi pulse is applied to lead-in 41. At the same time a positive on pulse is applied to conductor 42, and an oil pulse is applied to conductor 43; and a positive or on pulse is applied to lead-in 45, and a negative or 011 pulse is applied to lead-in 44. As a result, the electron stream from the cathode 31 will flow only through grids G2, G22, G31, and thence to collector #1, which represents an output for the #1 decimal digit. Thus, any collector electrode can be selectively charged by the electron stream in accordance with the binary number pulses applied in on and oil? pairs to the respective pairs of lead-ins 40-41, 42-43, 44-45.

While in the embodiment of Fig. 3, the tube illustrates only eight, i. e-., 2' decimal output channels, where n is three, it will be understood that anynumber of channels may be provided by adding more concentric grid systems according to the disclosure, and the number of output collector channels increases as 2, while n is the number of successive rows of gating grids.

If desired, the tube of Fig. 3 can be modified in accordance with the teaching of the embodiment of Figs. 1 and 2. In other words, instead of using a single collector electrode in back of each of the gating grids G30G37, one, two, or three such collector electrodes may be mounted in back of each of these grids. Such an embodiment is illustrated in Fig. 4. In the embodiment of Fig. 4, the parts which are identical with those of Fig. 3 bear the same designation numerals. The only difference is that associated with each of the said gating grids G30-G37 are respective one, two, or three collector electrodes. For example, in radial alignment with gating grids G31, G33 and G37, are respective single collector electrodes C C and C In radial alignment with each of the collector electrodes G32, G34, G36, are corresponding pairs of collector electrodes C -C C -C C -C while in radial alignment with the gating grid G35 is a set of three collectors C C C C01- lectors C C C C are connected together by a conductor 51 and thence to the corresponding coded output terminal, which for example may be the #1 terminal of a well-known Gray coding system. Likewise, collectors C C C C are connected together by a conductor 52 and thence to the #2 terminal of the Gray code wires. Similarly, collectors C C C and C are connected together by a conductor 53 and thence to the #3 output terminal of the Gray code wires. The #0 terminal of this Gray coded output is left blank. Therefore, by applying appropriate combinations of on and 011 binary pulses to the lead-ins 40-41, 42-43, 44-45, as described above in connection with Fig. 3, the Gray output terminals will be correspondingly energized in accordance with the following chart:

Binary Code Conductors Gray Code Conductors Decimal Digits 6 In the foregoing chart the letter x indicates that the corresponding coded wire has a voltage impressed thereon or is in the on condition, whereas the absence of the letter x indicates the corresponding coded wire is deenergized or in the ofF condition.

From the foregoing, it will be seen that the embodiments of Figs. 1 and 4 can be combined in series so as to convert decimal input signals applied to the input terminals of Fig. 1 so as to convert them into corresponding binary outputs. These binary outputs in turn can be connected to the binary input terminals 40-45 of a tube according to Fig. 4 to produce at the output of the tube of Fig. 4 the desired combinations of Gray coded wires in accordance with the above chart.

Various changes and modifications may be made in the disclosed embodiments without departing from the spirit and scope of the invention.

What is claimed is:

1. An electron tube for converting input signals in the binary code into corresponding output signals in the decimal system, comprising an evacuated envelope, an electron emitting cathode, a series of l to N pairs of binary coded input terminals, a set of n output electron collector electrodes each connected to a corresponding one of said output terminals and where n is 2 a series of N radially successive sets of gating control grids with the grids of each set being in circumferential array around the cathode and with the grids of each set spaced substantially the same distance from the cathode but with succesive sets at respectively greater distances from the cathode, the first set of gating grids nearest the cathode comprising two grids each subtending an angle of approximately A degrees with respect to the cathode, the next set of gating grids comprising four grids each subtending an angle of approximately A/Z degrees with respect to the cathode, the final set of gating grids comprising 2 grids each subtending an angle of approximately A/Z degrees with respect to'the cathode, means connecting the two grids of the first set each individually to a corresponding one of a first pair of said input terminals, means connecting the alternate grids of the second set together and thence to corresponding terminals of the second pair of input terminals, means connecting the alternate grids of the final set together and thence to corresponding terminals of the final pair of said input terminals, and each of said output electrodes being in alignment with a corresponding one of the gating grids of the said final set.

2. An electron tube according to claim 1 in which the angle A subtended by the first grids is approximately 3. An electron tube for converting input signals in the binary code into corresponding output signals in the decimal system, comprising an evacuated envelope, an electron emitting cathode, a series of N pairs of binary coded input terminals, a set of n output electron col lector electrodes each connected to a respective one of said output terminals, where n'is 2 a series of N sets of gating grids with the grids of the first set being spaced each a substantially uniform distance from the cathode and with the grids of each succeeding set being substantially uniformly spaced from the grids of the next preceding set, the first gating grid set nearest the cathode comprising two grids each subtending an angle of A degrees with respect to the cathode, the second gating grid set comprising four grids each subtending an angle of approximately A/ 2 degrees with respect to the cathode, the final gating grid set comprising 2 grids each subtending an angle of approximately A/2 degrees with respect to the cathode, means connecting the two grids of the first set each to a corresponding one of the first pair of binary input terminals, means connecting the alternate grids of the second set together and thence to corresponding ones of the second set of input terminals, means connecting the alternate grids of the final set together and thence to corresponding ones of the final set of input terminals, and each of said output electrodes being in alignment respectively with one corresponding grid of the final set of grids.

References Cited in the file of this patent UNITED STATES PATENTS 8 Rajchman Jan. 27, 1950 Brown Aug. 15, 1950 Schramm" Dec. 12', 1950 Skellett. Dec. 12; 1950 Rajchman June 26, 1951 Rochester Oct. 9, 1951 Depp Nov. 3, 1953 Maynard Oct. 9, 1956 Kates Mar. 5, 1957 FOREIGN PATENTS Great Britain Apr. 21, 1954 

